The present invention relates to a control apparatus for controlling gas flow in a molecular region and including a housing having a through-channel and a groove circumscribing the through-channel along a predetermined circumferential extent of the through-channel, and a control plate displaceable in its plane between an open position, in which the plate is located sidewise of the through-channel, and a closed position, in which the control plate crosses the through-channel, which control plate has a circumferential edge at least a portion of which is received in the circumscribing groove in the closed position of the control plate.
The molecular gas flow takes place in a vacuum region with a pressure of 10-6 bar of lower. The molecular gas flow also plays a certain role in the transient region, the pressure in which is below 10-3 bar. The region of the molecular gas flow is characterized in that the mean free path lengths of the molecules are inversely proportional to the pressure. The mean free path lengths is a measure of probability of a collision of a molecule with another molecule of its environment. The mean free path lenghts define paths of separate molecules between two collisions. The mean free path lengths are rather substantial in the above-mentioned vacuum region.
In the material processing technology, there exists a need to control or regulate such a molecular gas flow and as continuously as possible over a large region. However, up to the present, all attempts to control the molecular gas flow did not bring the desired results.
Accordingly, an object of the invention is to provide a control apparatus for controlling gas flow in a molecular region which would insure a continuous control of a molecular gas flow over a large region.